About 6,500 courthouse and backroom jobs in England and Wales are being lost and more courts closed under the government’s drive to modernise the justice system through online pleas and remote video hearings.

Details of the ambitious extent of the £1bn programme launched in 2016 emerged from a consultation process circulated by the senior judiciary on Wednesday.

The job loss figure underlines the radical nature of the transformation envisaged by HM Courts and Tribunals Service (HMCTS). The justice secretary, David Gauke, recently appointed Tim Parker, a former boss of Kwik-Fit and the AA, as chair of its board. Parker was once nicknamed the Prince of Darkness by trade unions for reportedly driving to a factory in a Porsche to announce mass job losses.

The senior judiciary has sent around four large documents explaining how the switch to digital working will affect the criminal, civil and family courts as well as tribunals. Feedback is being sought from judges.

There will be more remote video hearings, online pleas for minor offences, video replay facilities for jurors in their retiring rooms and fewer physical courtrooms.

The 6,500 job losses will be spread over the period from 2016 to 2022. The cuts are likely to cause further alarm in the public-funded branch of the legal profession as they come at a time when criminal barristers are refusing to handle new legal aid cases because of cuts to fees, and when the Law Society is warning that criminal solicitors are becoming extinct.

commitment to provide sufficient ushers in court, and “digital support officers” will be on hand to support judges in the courts of the future, it says. “The 460 buildings that made up the court estate has been reduced to 350 so far, with more reductions due to come.”

In the foreword, the lord chief justice, Lord Burnett of Maldon, says: “These reforms will deliver savings – a necessary condition for securing the financial support of the government – but they will transform the way we operate the system of justice for the benefit of the public and enhance the administration of justice.

“Our approach to this modernisation must be rooted in our shared commitment and dedication to improving the administration of justice and access to justice so that we continue to uphold the rule of law.”

HMCTS has begun piloting virtual hearings, including in tax tribunals in which claimants can participate from their homes via webcams.

The single justice procedure, introduced in 2016, will eventually apply to as many as 840,000 cases a year. Under this procedure, if defendants plead guilty either online or in writing, or do not engage with the court, the case will be judged on the papers by a single magistrate working with a legal adviser, and the decision and sentence will be recorded digitally. It will apply to summary, non-imprisonable offences where there is no identifiable victim. Some contested hearings may be conducted via videolinks.

A computer system is being introduced for all criminal cases in magistrates and crown courts, although national security cases will not be stored on it.

Non-judicial staff will be authorised to complete “routine box work” currently done by judges, such as applications to extend time for compliance with an order when there is no risk to the trial date or uncontested special measures applications.

There should be clear procedure rules for those accessing justice online “with limited legal advice”, the documents state. “Processes will be consistent, predictable and easier to understand, especially for litigants in person.”

There are comments from other senior judges in the documents, highlighting concerns over funding and disrepair in the courts. Sir Brian Leveson, the head of criminal justice in the courts, writes: “I appreciate that first thoughts will challenge the reduction of public funding in many different parts of the system but we have to persuade the government that, consistent with our fervent belief in access to justice and in the maintenance of excellence, we have done all that we can to be as efficient as possible.”

An HMCTS spokesperson said:“We are investing over £1bn to modernise the justice system – making it more convenient, easier to use, and providing better value for the taxpayer.

“As we increase the use of digital services, it makes sense to consider the role for court buildings and assess whether some are still necessary to provide effective access to justice.

“Since April 2016 we have raised £115m from the sale of underused court buildings – over £34m more than forecast, and every penny of this will be reinvested as part of our modernisation plans.”

The HMCTS workforce is 16,313, of whom just over 2,000 are agency staff.

The shadow justice secretary, Richard Burgon, said: “More staff cuts and court closures are yet another consequence of the government’s reckless decision to impose on the Ministry of Justice the deepest cuts of any department.

“The government should halt all further cuts and closures, at least until it has published its long awaited courts bill so that its worrying plans for the future of our courts system can be properly debated.”

The general secretary of the Public and Commercial Services Union, Mark Serwotka, said: “Our court system is in meltdown … Any further cuts will make their job impossible and those seeking to access justice will suffer as a consequence.”